Multiscale characterization of the micromechanics of pure Mg

An important limitation of wrought (rolled and extruded) Mg alloys is their inherent strong mechanical anisotropy, a consequence of their hexagonal closed- packed (hcp) lattice. Several reasons contribute to this effect. First, at room temperature, the critical resolved shear stresses (CRSSs) of basal and non-basal slip systems have very different values, spanning several orders of magnitude; second, twinning, a very common deformation mechanism in these materials, exhibits a pronounced polarity, i.e. its activation is dependent on the relative orientation between the c-axis and the applied stress; finally, both hot and cold deformation processing textures are often quite sharp and the way the activation of different slip systems is influenced by the local texture and grain boundary network is not clear. Together, these factors lead to a dependence of the dominant deformation mechanisms on the texture, grain size, testing mode (tension or compression) and the testing direction, resulting in large differences in yield stress values and strain-hardening responses. In this work, we adopt a multiscale characterization strategy to unravel the micromechanisms of pure Mg. First, we present a coupled experimental and simulation study on the nanoindentation of pure Mg at different temperatures to determine the critical resolved shear stress evolution of the different slip systems at the single crystal level [1-3]. For this, several indentations were performed at temperatures between RT and 300 °C in individual grains of a polycrystalline sheet of pure Mg with different crystallographic orientations. The deformation profile and the microstructure around the indents was analyzed by atomic force microscopy (AFM) and electron backscatter diffraction (EBSD), to determine the CRSS of the different slip systems without grain boundary effects. EBSD assisted trace analysis during in-situ SEM mechanical testing of cold-rolled polycrystalline Mg sheets was then used to account for the role of the local microstructure, such as the local texture and grain boundary network, on the activation of the different deformation modes, In particular, it was found that, with decreasing grain size, at room temperature, a clear transition from non-basal to basal-slip dominated flow takes place under tension [4] and a transition from twinning to basal slip takes place under compression [5]. On the other hand, a similar transition from twinning to basal slip takes place with increasing temperature and decreasing strain rate [6]. The emergence of basal slip as a dominant mechanism is shown to be due to increasing levels of connectivity between favorably oriented grains, which facilitate slip transfer across grain boundaries. This study emphasizes the complexity of the micromechanics of pure Mg, where the activation of different deformation modes is strongly affected, not only by their single crystal CRSS levels, but also by the local grain boundary networks and local texture emerging from processing

Assessment of culture and environment in the Adolescent Brain and Cognitive Development Study: Rationale, description of measures, and early data.

Neurodevelopmental maturation takes place in a social environment in addition to a neurobiological one. Characterization of social environmental factors that influence this process is therefore an essential component in developing an accurate model of adolescent brain and neurocognitive development, as well as susceptibility to change with the use of marijuana and other drugs. The creation of the Culture and Environment (CE) measurement component of the ABCD protocol was guided by this understanding. Three areas were identified by the CE Work Group as central to this process: influences relating to CE Group membership, influences created by the proximal social environment, influences stemming from social interactions. Eleven measures assess these influences, and by time of publication, will have been administered to well over 7,000 9-10 year-old children and one of their parents. Our report presents baseline data on psychometric characteristics (mean, standard deviation, range, skewness, coefficient alpha) of all measures within the battery. Effectiveness of the battery in differentiating 9-10 year olds who were classified as at higher and lower risk for marijuana use in adolescence was also evaluated. Psychometric characteristics on all measures were good to excellent; higher vs. lower risk contrasts were significant in areas where risk differentiation would be anticipated

An overview of alfalfa (Medicago sativa L.) situation in Argentina

From the approximately 3.2 million ha of alfalfa grown in Argentina in 2018, about 60% is planted as pure stands and 40% in mixtures with temperate forage grasses. Pure stands are primarily used for dairy and hay production, while mixtures with grasses are usually devoted to beef production. More than 426 varieties have been registered between 1980 and March 2018, and about 120 varieties are currently in the market. Among these varieties, 65% belong to fall dormancy (FD) rates 8-10 and 35% to FD 6-7. The majority of those cultivars come from private companies, either domestic or international. Most of the new releases are provided by USA and, to a lesser extent, Australian breeding programs; however, INTA’s varieties currently have about 15% market share. The National Alfalfa Cultivar Evaluation Network is being conducted by INTA Manfredi since 1992 in an attempt to help farmers in the process of choosing the most adapted varieties. This network has 17 locations across the country which represents the wide range of environmental conditions and production systems (rain fed or irrigated). Forage yield (t DM ha-1 year-1) and stand density (persistence) are statistically analyzed and published annually (Arolfo and Odorizzi, 2017). Results from the last 10 years show that average forage production for FD 5-7 cultivars ranges from 5 t (metric tons) DM ha-1 year-1 in Anguil (Semiarid Pampa Region-5 cuts) to 24 t DM ha-1 year-1 in Marcos Juárez (Sub-humid Pampa Region-6 cuts) under rain fed conditions; and 17.2 t DM ha-1 year-1 in Hilario Ascasubi (Southern Pampa Region-6 cuts) to 20 t DM ha-1 year-1 in Viedma (Northern Patagonia-6 cuts) under irrigation. For the non-dormant cultivars (FD 8-10), forage production ranges from 5.3 t DM ha-1 year-1 in Anguil (5 cuts) to 25.2 t DM ha-1 year-1 in Marcos Juárez (8 cuts) under rain fed conditions; and 17.3 t DM ha-1 year-1 in Catamarca (Northwestern Region-8 cuts) to 23 t DM ha-1 year-1 in Santiago del Estero (North-Western Region-8 cuts) under irrigation. In bovine production, rotational grazing is still very important in Argentina. Compared to other production systems, grazing alfalfa offers lower production costs and better utilization of alfalfa forage quality; on the other hand, it increases the risk of bloat and requires longer cattle finishing periods. Nonetheless, the use of feed-lot type operations has dramatically increased in the last 15 years. Utilization of corn or sorghum silage and alfalfa hay has become increasingly important for most dairy and beef production systems that use varied degrees of cattle confinement. Despite this, nearly 55% of milk is still produced in grazing-based systems in which alfalfa represents 50% (winter) to 80% (spring and summer) of the total diet.INTA. Centro Regional Córdoba. EEA Manfredi.Fil: Giletta, Martin Alfredo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Manfredi. Grupo Actividades Técnicas Complementarias; ArgentinaFil: Odorizzi, Ariel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Manfredi. Grupo de Mejoramiento Genético de Alfalfa, ArgentinaFil: Arolfo, Valeria. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Manfredi. Grupo de Mejoramiento Genético de Alfalfa; ArgentinaFil: Sanchez, Federico Raul. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Manfredi. Grupo Agricultura de Precisión Cosecha y Postcosecha; ArgentinaFil: Urrets Zavalia, Gastón. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Manfredi. Grupo Recursos Forrajeros; ArgentinaFil: Basigalup, Daniel Horacio. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Manfredi. Grupo Recursos Forrajeros; Argentin

Influencia de los estilos de vida físicamente activos y sedentarios en la percepción subjetiva de la salud y el bienestar de la juventud española

La presente comunicación se enmarca en un estudio financiado por el Consejo Superior de Deportes (CSD) (Ref. 007/UPB10/12). Uno de los objetivos específicos del estudio, en el que se basa la comunicación, es ampliar el conocimiento sobre la influencia de los estilos de vida físicamente activos y sedentarios en la percepción subjetiva de la salud y el bienestar de la juventud española

Spin reorientation and metamagnetic transitions in R F e0.5 C r0.5 O3 perovskites (R=Tb, Dy, Ho, Er)

In this work we present the magnetic structures and spin reorientation (SR) transitions of the mixed orthochromite-orthoferrite perovskites RFe0.5Cr0.5O3 (R=Tb, Dy, Ho, Er). Magnetization as a function of temperature and external magnetic field as well as neutron powder diffraction measurements were used to characterize the magnetic transitions, including the SR transitions in the transition metal sublattice and the ordering of the rare earth sublattice. The studied compounds order antiferromagnetically below 270 K in a Gx configuration compatible with the Γ4 representation. As temperature decreases, all the compounds show a SR transition from Gx (Γ4) to Gz (Γ2). This transition occurs in a wide temperature range, where both magnetic configurations coexist. Below this SR, the behavior in each case depends on the rare earth. HoFe0.5Cr0.5O3 shows Ho3+ sublattice ordering at a relatively high temperature (45 K). DyFe0.5Cr0.5O3 and ErFe0.5Cr0.5O3 show a second SR transition of the transition metal sublattice, from Gz (Γ2) to Gy (Γ1) at low temperatures (15 and 8 K, respectively). Below these temperatures a metamagnetic (MM) transition is observed for these two compounds at an external magnetic field of H ≈ 7 kOe. The fact that this is only observed for compounds showing Gz (Γ2) to Gy (Γ1) transition suggests that there is a correlation between the Gy (Γ1) order and the MM transition. Finally, TbFe0.5Cr0.5O3 is a peculiar case, since it is the only compound in this family that shows a re-entrant SR to Gx (Γ4) at very low temperatures. By combining these results with previous reports on RFeO3, RCrO3, and RFe0.5Cr0.5O3, we develop a method to qualitatively estimate the SR temperature and the type of transition. We also propose a complete magnetic phase diagram containing the SR transitions and R3+ ordering temperatures for all the RFe0.5Cr0.5O3 (R=Tb, Dy, Ho, Er, Tm, Yb, and Lu) compounds.Fil: Bolletta, Juan Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Pomiro, Fernando. Universidad Nacional del Litoral; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Física del Litoral. Universidad Nacional del Litoral. Instituto de Física del Litoral; ArgentinaFil: Sanchez, Rodolfo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comision Nacional de Energía Atómica. Gerencia de Área Investigaciones y Aplicaciones no Nucleares. Gerencia de Física (Centro Atómico Bariloche). División Resonancias Magnéticas; ArgentinaFil: Pomjakushin, Vladimir. Universidad Nacional de Cuyo; ArgentinaFil: Aurelio, Gabriela. Comision Nacional de Energía Atómica. Gerencia de Área Investigaciones y Aplicaciones no Nucleares. Gerencia de Física (Centro Atómico Bariloche). División Física de Metales; ArgentinaFil: Maignan, Antoine. Université de Caen Normandie; FranciaFil: Martin, Christine. Université de Caen Normandie; FranciaFil: Carbonio, Raul Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; Argentin

Treatment of subclinical hypothyroidism does not affect bone mass as determined by dual-energy X-ray absorptiometry, peripheral quantitative computed tomography and quantitative bone ultrasound in Spanish women.

INTRODUCTION: The results of studies examining the influence of subclinical hypothyroidism (SCH) and levothyroxine (L-T4) replacement therapy on bone have generated considerable interest but also controversy. The present research aims to evaluate the effects of L-T4 treatment on different skeletal sites in women. MATERIAL AND METHODS: A group of 45 premenopausal (mean age: 43.62 ±6.65 years) and 180 postmenopausal (mean age: 59.51 ±7.90 years) women with SCH who were undergoing L-T4 replacement therapy for at least 6 months were compared to 58 pre- and 180 postmenopausal women with SCH (untreated) matched for age. The mean doses of L-T4 were 90.88 ±42.59 µg/day in the premenopausal women and 86.35 ±34.11 µg/day in the postmenopausal women. Bone measurements were obtained using quantitative bone ultrasound (QUS) for the phalanx, dual-energy X-ray absorptiometry (DXA) for the lumbar spine and hip, and peripheral quantitative computed tomography (pQCT) for the non-dominant distal forearm. RESULTS: No differences were observed between patients and untreated controls in these bone measurements except in the bone mineral density (BMD) of the spine (p = 0.0214) in postmenopausal women, which was greater in treated women than in untreated controls. CONCLUSIONS: Our results indicate that adequate metabolic control through replacement treatment with L-T4 in pre- and postmenopausal women does not affect bone mass

Improvement of alfalfa forage quality and management through the down-regulation of MsFTa1

Alfalfa (Medicago sativa L.) is one of the most important forage crops worldwide. As a perennial, alfalfa is cut several times each year. Farmers face a dilemma: If cut earlier, forage nutritive value is much higher but regrowth is affected and the longevity of the stand is severely compromised. On the other hand, if alfalfa is cut later at full flower, stands persist longer, more biomass may be harvested, but the nutritive value diminishes. Alfalfa is a strict long‐days plant. We reasoned that by manipulating the response to photoperiod, we could delay flowering to improve forage quality and widen each harvesting window, facilitating management. With this aim, we functionally characterised the FLOWERING LOCUS T family of genes, represented by five members: MsFTa1, MsFTa2, MsFTb1, MsFTb2 and MsFTc. The expression of MsFTa1 correlated with photoperiodic flowering and its downregulation led to severe delayed flowering. Altogether, with late flowering, low expression of MsFTa1 led to changes in plant architecture resulting in increased leaf to stem biomass ratios and forage digestibility. By manipulating photoperiodic flowering we were able to improve the quality of alfalfa forage and management, which may allow farmers to cut alfalfa of high nutritive value without compromising stand persistence.Fil: Lorenzo, Christian Damián. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Gagliardi, Raul Pedro. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Antonietti, Mariana Sofía. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Sanchez Lamas, Maximiliano. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Mancini, Estefania. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Dezar, Carlos Alberto Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Agrobiotecnología de Rosario; ArgentinaFil: Vazquez, Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Agrobiotecnología de Rosario; ArgentinaFil: Watson, Geronimo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Agrobiotecnología de Rosario; ArgentinaFil: Yanovsky, Marcelo Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Cerdan, Pablo Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentin

Metallation‐induced heterogeneous dynamics of DNA revealed by single‐molecule FRET

The metallation of nucleic acids is key to wide‐ranging applications, from anticancer medicine to nanomaterials, yet there is a lack of understanding of the molecular‐level effects of metallation. Here, we apply single‐molecule fluorescence methods to study the reaction of an organo‐osmium anticancer complex and DNA. Individual metallated DNA hairpins are characterized using Förster resonance energy transfer (FRET). Although ensemble measurements suggest a simple two‐state system, single‐molecule experiments reveal an underlying heterogeneity in the oligonucleotide dynamics, attributable to different degrees of metallation of the GC‐rich hairpin stem. Metallated hairpins display fast two‐state transitions with a two‐fold increase in the opening rate to ~2 s‐1, relative to the unmodified hairpin, and relatively static conformations with long‐lived open (and closed) states of 5 s to ≥ 50 s. These studies show that a single‐molecule approach can provides new insight into metallation‐induced changes in DNA structure and dynamics

Cognitive Reserve Characteristics and Occupational Performance Implications in People with Mild Cognitive Impairment

The Cognitive Reserve hypothesis suggests that there are individual differences in the ability to cope with the pathologic changes in Alzheimer’s Disease. The proportion of elderly individuals has increased in recent years; this increase emphasizes the importance of early detection of mild cognitive impairment and the promotion of healthy ageing. The purpose of our study is to characterize cognitive reserve and occupational performance implications in people with mild cognitive impairment. 125 patients with mild cognitive impairment were enrolled. The Montreal Cognitive Assessments (MoCA) was used to evaluate cognitive status and the Cognitive Reserve Index Questionnaire (CRIq) as an indicator of cognitive reserve. Higher level of education was associated with higher MoCA scores (r = 0.290, p = 0.001). Positive significant correlations were observed between MoCA and total CRIq (r = 0.385, p < 0.001) as well as its three sub-domains, education (r = 0.231, p = 0.010), working activity (r = 0.237, p = 0.008) and leisure time (r = 0.319, p < 0.001). This study findings provide the importance of considering socio-behavioral factors in cognitive status. This research helps to describe the importance of engaging occupationally along the whole life-course as a potential protective factor in ageing, and includes a perspective of occupational therapy regarding the hypothesis of cognitive reserve.Depto. de EnfermeríaFac. de Enfermería, Fisioterapia y PodologíaTRUEpu

Nanoinformatics: developing new computing applications for nanomedicine

Nanoinformatics has recently emerged to address the need of computing applications at the nano level. In this regard, the authors have participated in various initiatives to identify its concepts, foundations and challenges. While nanomaterials open up the possibility for developing new devices in many industrial and scientific areas, they also offer breakthrough perspectives for the prevention, diagnosis and treatment of diseases. In this paper, we analyze the different aspects of nanoinformatics and suggest five research topics to help catalyze new research and development in the area, particularly focused on nanomedicine. We also encompass the use of informatics to further the biological and clinical applications of basic research in nanoscience and nanotechnology, and the related concept of an extended ?nanotype? to coalesce information related to nanoparticles. We suggest how nanoinformatics could accelerate developments in nanomedicine, similarly to what happened with the Human Genome and other -omics projects, on issues like exchanging modeling and simulation methods and tools, linking toxicity information to clinical and personal databases or developing new approaches for scientific ontologies, among many others